Fuel-control system for burners



I a I JOI/{Y A. 0051.5

J. A. DOBLE. FUEL CONTROL SYSTEM FOR BURNERS.

- APPLICATION FILED APR.29, 1918.

1,399,938, Patented Dec. 13, 1921.

WITNESS INVENTOR.

A TTORNE Y5 UNITED STATES PATENT OFFICE.

JOHN A. DOBLE, OF SAN FRANCISCO, CALIFORNIA, ASSIGNOR TO DOBLE L ABORA- TORIES, OF SAN FRANCISCO, CALIFORNIA, A CORPORATION OF CALIFORNIA.

FUEL-CONTROL SYSTEM FOR BURNERS.

Specification of Letters Patent.

Patented Dec. 13, 1921.

To all whom it may concern:

Be it known that I, JOHN A. DOBLE, a citizen ofv the United States, and a resident of the city and county of San Franclsco and State of California, have invented certain new and useful Fuel-Control Systems for Burners, of which the following is a specification.

The invention relates to devices for controlling the fiow of fuel to burners and particularly to burners associated with steam generating devices or other heat absorbing medium containing devices, and further to burners which include electric motors in their operating mechanism. I

An object of the invention is to provide means for stopping and starting the flow of fuel to the burner in accordance with variations in conditions within the steam genera-tor.

Another object of the invention is to provide means for causing a steady flow of fuel to the burner during its operation.

Another object of the invention is to provide means for preventing excess pressure in the fuel line.

A further object of the invention is to provide means for abruptly stopping the flow of fuel to the burner when the electric circuit of the motor is opened and for starting the supply when the circuit is closed.

The invention possesses other advantageous features, some of which, with the foregoing, will be set forth at length in the following description where I shall outline in full, that form of the invention which I have selected for illustration in the'drawing accompanying and forming part of the present specification. In said drawing I have shown one specific form of my invention, but it is to be understood that I do not limit myselfto such form'since the invention, as expressed in the claims, may be embodied in a plurality of forms. In the drawing I have shown my invention applied to a rotary burner in which the fuel is atomized by a r0- tating element to which the blower for supplying air for combustion is attached, so that both are rotated by the same motor, but it is to be understood that the invention is equally applicable to all types of burners in which an electric motor is used, either to atomize the liquid or to introduce the air for combustion.

The drawing is a diagrammatic representation of the fuel control system of, my in- 6 which is rotated by the motor to inducethe necessary air for combustion, into the casing. The fuel mixture thus produced is ignited by an electric spark which brid es the gap between-the electrode 7, arrange in the casing, and the cup, which forms the other electrode. The motor 4 is operated by current from the battery 8, and a hand operated switch 9 is employed for opening and closing the motor circuit. Arranged in parallel with the motor is a circuit containing an interrupter 12, preferably in the form of a commutator driven from the motor shaft and a transformer 14, the secondary of which is arranged in the ignition circuit.

Fuel is fed to the burner from the supply tank 15, by the pump 16, preferably a piston pump, which is driven from the motor shaft. From the pump, the fuel is forced through the conduit 17 to the valve 18. The valve 18 is provided with two connections, the conduit 19 leading to the burner and the conduit 21, leading back to the fuel supply pipe 22. The conduit 19 is provided with a regulating valve 23, which maintains a constant flow of fuel to the burner when the pump is in operation and the valve 18 is open. Arranged in the by-pass conduit 21 is a pressure regulating device, which operates to maintain the pressure of the fuel in the conduits 17, 19 and 21, substantially constant and to prevent excessive pressures in the fuel line. This device consists of a cylinder 24 inserted in the fuel line and through which the by-passed fuel passes. The cylinder is provided on its inner surface with a longitudinal groove 25 which extends part way toward the inlet end of the cylinder. Disposed in the cylinder is a piston 26 which is pressed by the spring 27 toward the inlet end of the cylinder. When the pressure increases, the piston is forced back, uncovering the groove and the fuel is permitted to flow through the by-pass line. The groove gradually increases in depth, so that the greater the piston is depressed, the

greater amount of fuel is by-passed. This device operates also as a cushioning device to compensate for the pressure pulsations produced by the ump.

' The position of the valve 18 is controlled by a solenoid 28 which surrounds the body of the valve and is so disposed with relation to the valve, that when the solenoid is energized the valve is raised from its seat, permitting the fuel to flow through the conduit 19 to the burner. When the solenoid circuit is open, the valve is seated and the fuel flows through the by-pass line. The solenoid 28 is arranged in the motor circuit, so that when the motor circuit is opened, the flow of fuel to the burner is immediately stopped, and that which is pumped due to the momentum of the motor, flows through the by-pass. When the motor circuit is closed, the valve is immediately opened and fuel is delivered to the burner.

Means are provided for opening and clos ing the motor-solenoid circuit in accordance with the variations in conditions in temperature and pressure within the steam generator. Arranged in the motor circuit is a flexible element 31 carrying a contact 32, which is movable, due to the flexure of the element, into and out of engagement with the fixed contact '33. Bearing'against one end of the element 31 is a lever 34, connected to an expansible rod' 35 arranged within the generator, so that an excessive increase of temperature will cause the 'expanding rod to flex the element sufliciently to open the circuit. Bearing against the other end of the element is a pressure actuated diaphragm 36, operated by the pressure of the steam within the generator to vary the flexure of the element. An excessive temperature or pressure will flex the element sufliciently to open the circuit and thereby cause the motor to stop and also stop the flow of fuel to the burner.

I claim:

1. The combination with a liquid fuel burner, of an electric motor operatively associated therewith, a circuit for said motor a conduit through which fuel is conveyed to said burner, a pump in said conduit, an

electrically operated valve in said conduit between the pump and the burner, a by-pass connecting the conduit on the pressure side of the pump with the conduit on the intake side of the pump and means in the by-pass connection opposing the How of liquid therethrough and operating to revent an excessive pressure in the con uit.

2. The combination with aliquid fuel burner, of a heat absorbing medium containing device associated therewith, a conduit through which fuel isconveyed to the burner, a .valve in said conduit, a single solenoid for opening and closing said valve,

a circuit for said solenoid and, means operative by varying conditions in the said device for opening and closing said circuit.

3. The combination with a (liquid fuel burner, of a heat absorbing medium containing device associated therewith, a fuel 'pump, a conduit connecting the pump and the burner, a valve in said conduit, a solenoid for opening and closing said valve, a circuit for said solenoid, means operative by variations in conditions in the said device for opening and closing said circuit and a by-pass conduit connecting said first mentioned conduit on the pump side of the valve with the intake side of the pump.

4, The combination with. a: liquid fuel burner, of a heat absorbing medium containing device associated therewith, an elec tric motor operatively associated with said burner, a conduit through which fuel is conveyed to the burner, a pump in said conduit, a valve for opening and closing said conduit, a solenoid for actuating said valve, a circuit including said motor and solenoid and means operated by variations in conditions within the said device on the pressure side of the pump for opening and closing said circuit.

5. The combination with aliquid fuel burner, of a heat absorbing medium containing device associated therewith, a conduit through which fuel is conveyed to the burner, a pump in said conduit, a valve in said conduit between the pump 7 and the burner,- a solenoid for opening and closing said valve, a circuit for said solenoid, means operative by variations in conditions in the said device for opening and closing said circuit, 'a bypass conduit connecting said first-mentioned conduit on the pump side of the valve with the intake side of the pump and a cushioning device arranged in said by-pass conduit.

6. The combination with a liquid fuel burner, of a heat absorbing medium containing device associated therewith, an electric motoroperatively associated with said burner, a conduit through which fuel is con veyed to the burner, a pump in said conduit, a valve for opening and closing said conduit, a solenoid for actuatingsaid valve, an electric circuit including said motor and solenoid, means operated by variations in temperature within said heat absorbing medium containing device for opening and closing said circuit, and a by-pass conduit connecting said first-mentioned conduit on the pump side of the valve with side of the pump.

In testimony whereof, I hereunto set my hand at San Francisco, California, this 19th day of April, 1918. v

JOHN A. DO'BLE.

In presence of- H. G. PROST.

the intake 

